Planar immersion lens with metasurfaces

The solid immersion lens is a powerful optical tool that allows light entering material from air or vacuum to focus to a spot much smaller than the free-space wavelength. Conventionally, however, they rely on semispherical topographies and are non-planar and bulky, which limits their integration in many applications. Recently, there has been considerable interest in using planar structures, referred to as metasurfaces, to construct flat optical components for manipulating light in unusual ways. Here, we propose and demonstrate the concept of a planar immersion lens based on metasurfaces. The resulting planar device, when placed near an interface between air and dielectric material, can focus electromagnetic radiation incident from air to a spot in material smaller than the free-space wavelength. As an experimental demonstration, we fabricate an ultrathin and flexible microwave lens and further show that it achieves wireless energy transfer in material mimicking biological tissue

Decoration of the truncated tetrahedron - an Archimedean polyhedron - to produce a new class of convex equilateral polyhedra with tetrahedral symmetry

The Goldberg construction of symmetric cages involves pasting a patch cut out of a regular tiling onto the faces of a Platonic host polyhedron, resulting in a cage with the same symmetry as the host. For example, cutting equilateral triangular patches from a 6.6.6 tiling of hexagons and pasting them onto the full triangular faces of an icosahedron produces icosahedral fullerene cages. Here we show that pasting cutouts from a 6.6.6 tiling onto the full hexagonal and triangular faces of an Archimedean host polyhedron, the truncated tetrahedron, produces two series of tetrahedral (T-d) fullerene cages. Cages in the first series have 28n(2) vertices (n >= 1). Cages in the second (leapfrog) series have 3 x 28n(2). We can transform all of the cages of the first series and the smallest cage of the second series into geometrically convex equilateral polyhedra. With tetrahedral (T-d) symmetry, these new polyhedra constitute a new class of "convex equilateral polyhedra with polyhedral symmetry". We also show that none of the other Archimedean polyhedra, six with octahedral symmetry and six with icosahedral, can host full-face cutouts from regular tilings to produce cages with the host's polyhedral symmetry

The NDR/LATS Family Kinase Cbk1 Directly Controls Transcriptional Asymmetry

Cell fate can be determined by asymmetric segregation of gene expression regulators. In the budding yeast Saccharomyces cerevisiae, the transcription factor Ace2 accumulates specifically in the daughter cell nucleus, where it drives transcription of genes that are not expressed in the mother cell. The NDR/LATS family protein kinase Cbk1 is required for Ace2 segregation and function. Using peptide scanning arrays, we determined Cbk1′s phosphorylation consensus motif, the first such unbiased approach for an enzyme of this family, showing that it is a basophilic kinase with an unusual preference for histidine −5 to the phosphorylation site. We found that Cbk1 phosphorylates such sites in Ace2, and that these modifications are critical for Ace2′s partitioning and function. Using proteins marked with GFP variants, we found that Ace2 moves from isotropic distribution to the daughter cell nuclear localization, well before cytokinesis, and that the nucleus must enter the daughter cell for Ace2 accumulation to occur. We found that Cbk1, unlike Ace2, is restricted to the daughter cell. Using both in vivo and in vitro assays, we found that two critical Cbk1 phosphorylations block Ace2′s interaction with nuclear export machinery, while a third distal modification most likely acts to increase the transcription factor's activity. Our findings show that Cbk1 directly controls Ace2, regulating the transcription factor's activity and interaction with nuclear export machinery through three phosphorylation sites. Furthermore, Cbk1 exhibits a novel specificity that is likely conserved among related kinases from yeast to metazoans. Cbk1 is functionally restricted to the daughter cell, and cannot diffuse from the daughter to the mother. In addition to providing a mechanism for Ace2 segregation, these findings show that an isotropically distributed cell fate determinant can be asymmetrically partitioned in cytoplasmically contiguous cells through spatial segregation of a regulating protein kinase

Dynamics of light propagation in spatiotemporal dielectric structures

Propagation, transmission and reflection properties of linearly polarized plane waves and arbitrarily short electromagnetic pulses in one-dimensional dispersionless dielectric media possessing an arbitrary space-time dependence of the refractive index are studied by using a two-component, highly symmetric version of Maxwell's equations. The use of any slow varying amplitude approximation is avoided. Transfer matrices of sharp nonstationary interfaces are calculated explicitly, together with the amplitudes of all secondary waves produced in the scattering. Time-varying multilayer structures and spatiotemporal lenses in various configurations are investigated analytically and numerically in a unified approach. Several new effects are reported, such as pulse compression, broadening and spectral manipulation of pulses by a spatiotemporal lens, and the closure of the forbidden frequency gaps with the subsequent opening of wavenumber bandgaps in a generalized Bragg reflector

Multi-component optical solitary waves

We discuss several novel types of multi-component (temporal and spatial) envelope solitary waves that appear in fiber and waveguide nonlinear optics. In particular, we describe multi-channel solitary waves in bit-parallel-wavelength fiber transmission systems for high performance computer networks, multi-colour parametric spatial solitary waves due to cascaded nonlinearities of quadratic materials, and quasiperiodic envelope solitons due to quasi-phase-matching in Fibonacci optical superlattices.Comment: 12 pages, 11 figures; To be published in: Proceedings of the Dynamics Days Asia-Pacific: First International Conference on Nonlinear Science (Hong-Kong, 13-16 July, 1999), Editor: Bambi Hu (Elsevier Publishers, 2000

Trait coping styles and the maternal neural and behavioral sensitivity to an infant

During the postpartum period, new mothers experience drastic changes in their body, brain, and life circumstances. Stress from the emotional and physical demands of caring for an infant is associated with negative mood and parenting outcomes. The use of active coping strategies can increase mothers&rsquo; resilience during the postpartum period. However, little is known about the association between coping styles and maternal brain responses to infant cues. In the current study, we examined the associations among trait coping style, maternal brain responses, and behavioral sensitivity in a socioeconomically diverse sample of first-time mothers (N&thinsp;=&thinsp;59). The use of more active trait coping strategies compared to passive coping strategies was associated with increased brain responses to infant cry sounds in brain regions that are critically involved in motivation and emotion regulation&mdash;substantia nigra, anterior cingulate gyrus, and inferior frontal gyrus. Increased brain activations in the midbrain and anterior cingulate gyrus were further associated with higher levels of maternal sensitivity observed during interactions with the infant. Thus, the findings provide support for mothers&rsquo; use of more active coping styles to promote neural and behavioral resilience for a positive transition to parenthood. &nbsp;</p

Diaryl hydroxylamines as pan or dual inhibitors of indoleamine 2,3-dioxygenase-1, indoleamine 2,3-dioxygenase-2 and tryptophan dioxygenase

Tryptophan (Trp) catabolizing enzymes play an important and complex role in the development of cancer. Significant evidence implicates them in a range of inflammatory and immunosuppressive activities. Whereas inhibitors of indoleamine 2,3-dioxygenase-1 (IDO1) have been reported and analyzed in the clinic, fewer inhibitors have been described for tryptophan dioxygenase (TDO) and indoleamine 2,3-dioxygenase-2 (IDO2) which also have been implicated more recently in cancer, inflammation and immune control. Consequently the development of dual or pan inhibitors of these Trp catabolizing enzymes may represent a therapeutically important area of research. This is the first report to describe the development of dual and pan inhibitors of IDO1, TDO and IDO2

Nuisance Bleeding With Prolonged Dual Antiplatelet Therapy After Acute Myocardial Infarction and its Impact on Health Status

ObjectivesThe purpose of this study was to examine the incidence of nuisance bleeding after AMI and its impact on QOL.BackgroundProlonged dual antiplatelet therapy (DAPT) is recommended after acute myocardial infarction (AMI) to reduce ischemic events, but it is associated with increased rates of major and minor bleeding. The incidence of even lesser degrees of post-discharge “nuisance” bleeding with DAPT and its impact on quality of life (QOL) are unknown.MethodsData from the 24-center TRIUMPH (Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status) study of 3,560 patients, who were interviewed at 1, 6, and 12 months after AMI, were used to investigate the incidence of nuisance bleeding (defined as Bleeding Academic Research Consortium type 1). Baseline characteristics associated with “nuisance” bleeding and its association with QOL, as measured by the EuroQol 5 Dimension visual analog scale, and subsequent re-hospitalization were examined.ResultsNuisance (Bleeding Academic Research Consortium type 1) bleeding occurred in 1,335 patients (37.5%) over the 12 months after AMI. After adjusting for baseline bleeding and mortality risk, ongoing DAPT was the strongest predictor of nuisance bleeding (rate ratio [RR]: 1.44, 95% confidence interval [CI]: 1.17 to 1.76 at 1 month; RR: 1.89, 95% CI: 1.35 to 2.65 at 6 months; and RR: 1.39, 95% CI: 1.08 to 1.79 at 12 months; p < 0.01 for all comparisons). Nuisance bleeding at 1 month was independently associated with a decrement in QOL at 1 month (−2.81 points on EuroQol 5 Dimension visual analog scale; 95% CI: 1.09 to 5.64) and nonsignificantly toward higher re-hospitalization (hazard ratio: 1.20; 95% CI: 0.95 to 1.52).ConclusionsNuisance bleeding is common in the year after AMI, associated with ongoing use of DAPT, and independently associated with worse QOL. Improved selection of patients for prolonged DAPT may help minimize the incidence and adverse consequences of nuisance bleeding

Nuisance Bleeding With Prolonged Dual Antiplatelet Therapy After Acute Myocardial Infarction and its Impact on Health Status

ObjectivesThe purpose of this study was to examine the incidence of nuisance bleeding after AMI and its impact on QOL.BackgroundProlonged dual antiplatelet therapy (DAPT) is recommended after acute myocardial infarction (AMI) to reduce ischemic events, but it is associated with increased rates of major and minor bleeding. The incidence of even lesser degrees of post-discharge “nuisance” bleeding with DAPT and its impact on quality of life (QOL) are unknown.MethodsData from the 24-center TRIUMPH (Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status) study of 3,560 patients, who were interviewed at 1, 6, and 12 months after AMI, were used to investigate the incidence of nuisance bleeding (defined as Bleeding Academic Research Consortium type 1). Baseline characteristics associated with “nuisance” bleeding and its association with QOL, as measured by the EuroQol 5 Dimension visual analog scale, and subsequent re-hospitalization were examined.ResultsNuisance (Bleeding Academic Research Consortium type 1) bleeding occurred in 1,335 patients (37.5%) over the 12 months after AMI. After adjusting for baseline bleeding and mortality risk, ongoing DAPT was the strongest predictor of nuisance bleeding (rate ratio [RR]: 1.44, 95% confidence interval [CI]: 1.17 to 1.76 at 1 month; RR: 1.89, 95% CI: 1.35 to 2.65 at 6 months; and RR: 1.39, 95% CI: 1.08 to 1.79 at 12 months; p < 0.01 for all comparisons). Nuisance bleeding at 1 month was independently associated with a decrement in QOL at 1 month (−2.81 points on EuroQol 5 Dimension visual analog scale; 95% CI: 1.09 to 5.64) and nonsignificantly toward higher re-hospitalization (hazard ratio: 1.20; 95% CI: 0.95 to 1.52).ConclusionsNuisance bleeding is common in the year after AMI, associated with ongoing use of DAPT, and independently associated with worse QOL. Improved selection of patients for prolonged DAPT may help minimize the incidence and adverse consequences of nuisance bleeding